A cell-free system has been obtained from Bacillus subtilis which carried out transcription and translation as measured by leucine-H3 incorporation into TCA-precipitable material. The system consists of an "S-30" extract, DNA from phage B22, and the necessary cofactors, amino acids, and nucleotides. The system is inhibited 75-90% by 25 microgram/ml of puromycin, and 30-50% by rifampin (25 microgram/ml). Omission of the DNA template inhibits the system to the same extent as rifampin. The incorporation of leucine-H3 is linear for 10 min and then levels off. Addition of protease inhibitors prevents rapid loss of radioactivity from the TCA-precipitable material. Work is in progress to improve the DNA dependency of the system, and to demonstrate, using phage B22 antiserum, the formation of phage coat protein. Subsequently, we intend to demonstrate the in vitro synthesis of sporulation-specific proteins and to use the system to assay for regulatory factors which control the synthesis of sporulation-specific proteins. Briefly, this will involve addition of suspected regulatory proteins isolated from sporulating cells to cell-free systems prepared from vegetative cells in an attempt to obtain sporulation-specific synthesis.